470 ohm resistor or about the same value will work. I used the smaller resistors because it’s way easier to fit it inside. It depends on your led, i like them bright but not too much, some use 1k instead. You can calculate here : http://led.linear1.org/1led.wiz

You basicly just need to solder the led on the resistor and jack, then i added some heatshrink 6mm but it’s not really needed. There’s too much solder in there but it was the first i made, practice makes perfect!